. >> reporter: when president obama asked us to stay vigilant in the wake of the attacks, he may not have foreseen this. bomb-sniffing dogs and robots working overtime. americans seeing something and saying something in droves. >> you feel safer by seeing it but brings it to the forefront of what could happen. >> reporter: a rash of suspicious packages called in to 911 tuesday. >> they located an abandoned box in the trash can that's suspicious in nature. it has wires coming out of it. >> reporter: a bomb-sniffing dog took out this hair dryer. in new jersey, an unattended bag shut down the pat train. police in new york city fielded 77 such reports in less than 24 hours, three times the norm. >> it would be easier if we just did pay attention, but if yesterday doesn't refresh your memory, i don't know what would. >> reporter: the epicenter of the jitters quite justifiably boston, where streets this morning are filled with armored vehicles, heavily armed cops and the national guard. at logan airport officials removed all passengers from a u.s. air flight because of concerns over a stra